Lee Westwood reclaimed the world number one ranking after he triumphed at the Indonesian Masters and Luke Donald failed to win The Heritage tournament.
Donald knew victory would take him to top spot but was beaten by Brandt Snedeker in a sudden-death play-off.
In Jakarta, Westwood took a five-stroke lead into the final round but that was cut to one shot on a tense day.
However, three birdies coming home was enough for a total of 19 under, three clear of Thailand's Thongchai Jaidee.
Jaidee ended with seven birdies in a superb bogey-free round of 65 while Australian Marcus Both, Siddikur of Bangladesh, Korea's Park Hyun-bin and Thailand's Thitiphun Chuayprakong finished three shots further back.
But a bogey at the second and then eight straight pars allowed the field to close in.
Westwood, 38 on Sunday, struggled with his putting but birdies at the 11th and 12th as well as a three at the 16th put him on the brink of victory.
He had to wait to celebrate his win, however, as play was suspended because of the threat of lightning with Westwood having played his tee shot at the last.
But after a spell in the clubhouse, Westwood returned in the rain to make a par five at 18th.
"It was quite a day really," said Westwood. "I knew it wasn't going to be easy with a five-shot lead.
"I'm experienced enough to know that patience is the key. I hit the ball great but didn't hit the putts when it mattered."